AP BIO: LAB 9 – VIRTUAL
Name
This lab was not completed at school due to the time constraints. Therefore, you will complete the lab “virtual” style
which will allow you to learn the objectives, gather, and analyze data. Go to the following website and complete AP BIO
LAB #9 – PLANT TRANSPIRATION (http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html)
1. State the objectives of this lab.
a. .
b. .
2. Record all data in the following data chart.
Plant
Normal
Arrowhead
Coleus
Devil’s Ivy
Dieffenbachia
English Ivy
Geranium
Rubber Plant
Zebra Plant
Rate of transpiration
per minute 
With fan
With heater
With Lamp
3. Describe experimental controls used in the investigation.
4. What environmental factors that you tested increased the rate of transpiration?
5. What environmental factors that you tested decreased the rate of transpiration?
6. Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others?
Why?
7. Which species of plants that you tested had the highest transpiration rates? Why do you think different species
of plants transpire at different rates?
8. Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be
affected?
9. Describe the process of transpiration in vascular plants.
10. Name 3 functions of transpiration.
11. How is the molecular structure of water significant to the transport of water in plant?
12. Explain the purpose of each of the following structure with regards to transpiration.
a. Cuticle
b. Guard cells
c. Leaf hairs
13. Place the following terms in the proper column:
o Found in stems
o Thin-walled, many-sided cels
o Dead at maturity
o Contain lignin
Collenchymas
Parenchyma
o
o
o
o
Thick-walled, irregularly shaped
Photosynthetic cells
Leaf ground tissue
Found near vascular bundels
Sclerenchyma
14. You came to class one morning and found the classroom plant looking wilted and unhealthy. You watered the
plant and by 6th period, the plant appeared rigid and healthy. What happened after you watered it?
15. Compare and contrast bryophytes and tracheophytes.
16. Do you think the number of stomata on the underside of a leaf is more, less, or the same as on the upper
surface of a leaf? Explain your answer.
17. One of the following statements is NOT true. Decide which one if false and explain your answer.
a. The guard cells of non-desert plants often close during the daytime and open at night to conserve water.
b. The guard cells of desert plants often close during the daytime and open at night to conserve water.
18. When you receive a bouquet of flowers, it is recommended that you cut a couple of inches off of the stems
before placing them in a vase. Why do you think this is?